*{
    margin:0;
    padding:0;
}
html,body{
    height:100%;
    width: 100%;
}
.bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

#center {
    position: absolute;
    margin-left: auto;
    margin-right: auto;
    height: 500px;
    width: 700px;
    text-align: center;
    padding: 20px;
    left: 0;
    top: 15%;
    right: 0;
}

#btn_div {
    padding: 20px;
    width: 100%;
    display: flex;
    justify-content: center;
}

.btn {
    margin: 0px 30px 0px 70px;
}

#login
{
    width:200px;
}

#register
{
    width:200px;
}

.input-group
{
    padding:20px;
}

.footer {
    left: 40%;
    width: 100%;
    position: fixed;
    bottom: 10px;
}

#username {
    height: 40px;
    border: 1px solid #ced4da;
    border-radius: .25rem;
}
#yan{
    height: 40px;
    border: 1px solid #ced4da;
    border-radius: .25rem;
}
#password {
    height: 40px;
    border: 1px solid #ced4da;
    border-radius: .25rem;
}

#password2 {
    height: 40px;
    border: 1px solid #ced4da;
    border-radius: .25rem;
}

#passwordeye {
    height: 40px;
    border-radius: .25rem;
    border: 1px solid #ced4da;
    border-radius: .25rem;
    background-color: white;
}

#password2eye {
    height: 40px;
    border-radius: .25rem;
    border: 1px solid #ced4da;
    border-radius: .25rem;
    background-color: white;
}

#span_username {
    width: 80px;
    text-align: right;
    padding-top: 5px;
    font-weight:700;
}
#span_yan{
    width: 80px;
    text-align: right;
    padding-top: 5px;
}
#span_password {
    width: 80px;
    text-align: right;
    padding-top: 5px;
    font-weight:700;

}

#span_password2 {
    width: 80px;
    text-align: right;
    padding-top: 5px;
    font-weight:700;
}

#yzm{
    width: 80px;
    text-align: right;
    padding-top: 5px;
    font-weight:700;
}

#yzm2{
    width:  200px;
    margin-right: 20px;
    height: 40px;
    border: 1px solid #ced4da;
    border-radius: .25rem;
}

#imgyzm{
    width:  100px;
    height: 40px;
    border-radius: .25rem;
}
#h1{
    font-size: 44px;
    text-align: center;
    padding-bottom: 40px;
}